NASA discovers glitch, scrubs launch

Shuttle a no-go

Posted: Thursday, July 14, 2005

By Mike SchneiderAssociated Press

CAPE CANAVERAL, Fla. - A faulty fuel-gauge reading forced NASA to call off Wednesday's launch of Discovery on the first shuttle flight since the Columbia disaster more than two years ago. The mission was put off until at least Saturday.

The decision to scrub the launch came with less than 2 1/2 hours to go, while the seven astronauts were boarding the spacecraft for their journey to the international space station. Up until then, a thunderstorm over the launch site looked like the only potential obstacle.

The problem involved one of the external fuel tank's four hydrogen fuel sensors, which are responsible for making sure the spacecraft's main engines shut down during the ascent when the tank runs out of fuel. A launch could end in tragedy if the engines cut out too early or too late.

A similar sensor problem cropped up intermittently during a launch pad test back in April, and NASA has been baffled as to the source of the trouble ever since.

"It's not a setback at all. We're fine if we go anytime in the launch window," NASA Administrator Michael Griffin said. "We had one mission for the Defense Department that scrubbed 14 times. This is nothing!"

The space agency has until the end of July to launch Discovery, after which it will have to wait until September - a window dictated by both the position of the space station and NASA's desire to hold a daylight liftoff in order to photograph the shuttle during its climb to orbit.

NASA officials said it not clear whether the problem is with the sensor itself or with the cables or the electronics boxes aboard Discovery.